The present invention relates to a method and apparatus for controlling the braking pressure in an automotive vehicle brake system equipped with an ABS system and including a brake power booster operable by an electric control element, wherein the rotational speed of the individual vehicle wheels is determined.
A control method of this type is disclosed in German patent application No. 42 17 409, for example. In the implementation of the method described in the application, the braking pressure introduced into the wheel brake is compared with a memorized braking pressure nominal value, and the brake power booster is operated in order to vary the boosting force as a function of the comparison result. A disadvantage of this known method is the high costs incurred by the pressure measurement.
German patent application No. 42 38 333 discloses a vacuum brake power booster including a control valve which is electrically operable by an electromagnet. The electromagnet interacting with the valve member of the control valve is rigidly connected to a valve piston which operates the control valve mechanically. The valve member defines a pneumatic chamber in a control housing accommodating the control valve. The pneumatic chamber is connected to the ventilatable working chamber of the brake power booster by way of passages. Thus, the valve member is permanently pressure-balanced.